Cleanup ISA string setting

NonerKao · palmer-dabbelt · commit e8be53023302 · 2018-10-22T17:02:23.000-07:00
This patch cleanup the MARCH string passing to both compiler and
assembler.  Note that the CFLAGS should not contain "fd" before we
have mechnisms like kernel_fpu_begin/end in other architectures.

Signed-off-by: Alan Kao &lt;alankao@andestech.com&gt;
Cc: Greentime Hu &lt;greentime@andestech.com&gt;
Cc: Vincent Chen &lt;vincentc@andestech.com&gt;
Cc: Zong Li &lt;zong@andestech.com&gt;
Cc: Nick Hu &lt;nickhu@andestech.com&gt;
Signed-off-by: Palmer Dabbelt &lt;palmer@sifive.com&gt;
diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile
@@ -28,30 +28,27 @@ ifeq ($(CONFIG_ARCH_RV64I),y)
 	
 	KBUILD_CFLAGS	+= $(call cc-ifversion, -ge, 0500, -DCONFIG_ARCH_SUPPORTS_INT128)
 
-	KBUILD_MARCH = rv64im
 	KBUILD_LDFLAGS += -melf64lriscv
 else
 	BITS := 32
 	UTS_MACHINE := riscv32
 
 	KBUILD_CFLAGS += -mabi=ilp32
 	KBUILD_AFLAGS += -mabi=ilp32
-	KBUILD_MARCH = rv32im
 	KBUILD_LDFLAGS += -melf32lriscv
 endif
 
 KBUILD_CFLAGS += -Wall
 
-ifeq ($(CONFIG_RISCV_ISA_A),y)
-	KBUILD_ARCH_A = a
-endif
-ifeq ($(CONFIG_RISCV_ISA_C),y)
-	KBUILD_ARCH_C = c
-endif
-
-KBUILD_AFLAGS += -march=$(KBUILD_MARCH)$(KBUILD_ARCH_A)fd$(KBUILD_ARCH_C)
+# ISA string setting
+riscv-march-$(CONFIG_ARCH_RV32I)	:= rv32im
+riscv-march-$(CONFIG_ARCH_RV64I)	:= rv64im
+riscv-march-$(CONFIG_RISCV_ISA_A)	:= $(riscv-march-y)a
+riscv-march-y				:= $(riscv-march-y)fd
+riscv-march-$(CONFIG_RISCV_ISA_C)	:= $(riscv-march-y)c
+KBUILD_CFLAGS += -march=$(subst fd,,$(riscv-march-y))
+KBUILD_AFLAGS += -march=$(riscv-march-y)
 
-KBUILD_CFLAGS += -march=$(KBUILD_MARCH)$(KBUILD_ARCH_A)$(KBUILD_ARCH_C)
 KBUILD_CFLAGS += -mno-save-restore
 KBUILD_CFLAGS += -DCONFIG_PAGE_OFFSET=$(CONFIG_PAGE_OFFSET)
 
